Direct Ammonia Fuel Cell Technology
An anion-exchange-membrane fuel cell architecture designed to convert ammonia directly into DC electricity.
In the 3D cell: NH₃ enters through the anode end plate and the anode exhaust (intended product: N₂) leaves through its second port. Air enters through the cathode end plate and the cathode exhaust leaves through its second port. OH⁻ ions cross the membrane from cathode to anode, and electrons flow from the anode current collector through the bulb to the cathode.
Current development architecture
The membrane thickness, large-cell geometry and final stack configuration remain part of the engineering optimisation programme.
One electrochemical conversion step
OH⁻ ions move through the anion-exchange membrane from cathode to anode. Electrons travel through the external circuit from anode to cathode.
Reference Half-reactions as reported for AEM direct ammonia fuel cells (Lan & Tao; J. Power Sources). Simplified overall reaction. Intended electrochemical products: N₂ and H₂O. Actual exhaust composition must be experimentally characterised for unreacted NH₃ and other species; it depends on fuel utilisation, crossover, operating conditions and exhaust treatment.
Designed around direct fuel use.
What limits DAFC performance?
H2ONE's development programme is designed around these known technical limitations rather than assuming that small-cell performance automatically scales. See the engineering risk register →
Four ways to power a commercial vehicle.
| Battery EV | Cracker + H₂ fuel cell | Direct-ammonia SOFC | H2ONE AEM DAFC | |
|---|---|---|---|---|
| Primary energy carrier | Grid electricity in a battery | NH₃, cracked to H₂ on board | NH₃ | NH₃ |
| External cracker | Not applicable | Yes | No (internal reforming at high temperature) | No |
| Operating temperature | Ambient | Hot cracker (e.g. GenCell FOX, <700 °C) | 600–900 °C | ≈70 °C (experimental reference) |
| Start-up complexity | Low | Cracker heat-up before full power | Slow heat-up and thermal cycling | Low-temperature; start-up behaviour still to be validated |
| Technology maturity | Commercial | Early commercial / demonstration | Demonstration | Laboratory cell |
| Current H2ONE status | Keeps the same electric drivetrain | Not pursued | Not pursued | 25 cm² cell measured; large-area cells in development |
Reference Based on public descriptions of each approach. H2ONE's column reflects development status and targets, not a finished product. Each approach has different strengths; this is a positioning map, not a ranking.
MATLAB connects the cell to the vehicle.
Experimental polarisation data is used to calibrate the engineering model. The model is then used to investigate:
Simulation supports engineering decisions. It does not replace validation.
Model scope
Simulated- large-area cell performance retention
- membrane-thickness sensitivity
- ammonia and air demand
- stack cell count
- stack voltage and current
- contact resistance losses
- balance-of-plant demand
- vehicle road load
- gradient performance
- transient buffer requirements
- range and fuel-consumption sensitivities
One platform, later.
Commercial mobility comes first. Once the vehicle stack is validated, the same direct-ammonia platform may be adapted for other uses. Each will need its own validation and approvals.